Devices for occluding, or blocking, a patient's eye are used for several types of clinical procedures. For example, such devices are commonly used during monocular eye examinations to test the differences in visual acuity between a patient's eyes. Occluding devices can be non-disposable or disposable, but there are potential problems associated with each.
A common non-disposable occluding device used in monocular eye testing procedures is generally paddle-shaped and is held up to a patient's eye to occlude the eye. Either a clinician or the patient must hold this type of occluding device. This may be undesirable, however, because when the clinician holds the occluding device, the clinician's ability to move relative to the patient during a procedure is limited. In addition, elderly patients or children may have difficulty holding the occluding device for the necessary duration of the procedure. In addition, this type of occluding device presents the risk of transferring diseases because the occluding device is reused, and may come into contact with eye secretions of various patients.
In another type of non-disposable occluding device, a fabric patch is held over the patient's eye by an elastic band placed around the patient's head, similar in appearance to a conventional “pirate's patch.” Typically, this type of patch is used in conjunction with a piece of tissue placed between the patch and the patient's eye, and the tissue remains in compressive contact with the patient's eyelid while the patch is worn. Such patches are basically flat, however, and offer limited adjustment, other than the tightness around the patient's head. In addition, after this type of patch is removed, the patient's eye previously covered by the patch takes a period of time to adjust following its compression with the tissue and the patch.
A disposable occluding device is described in U.S. Pat. No. 6,149,615 to Gallamore, which is directed to an eye patch that can be used for the treatment of Amblyopia, or lazy eye. Gallamore discloses that patches are placed over a patient's good eye to regain visual function in the other eye, and that such patches may be worn for months at a time. The patient's eye is closed while the patch is worn. Gallamore's eye patch includes a foam pad adhered to an outer membrane, which extends beyond the periphery of the foam pad. The outer membrane of Gallamore's eye patch includes adhesive entirely surrounding the foam pad to securely adhere the eye patch to a patient's face while completely obscuring the patient's vision. Gallamore describes that the foam pad is required to support the eye patch in a concavo-convex shape. It is neither economical nor easy to use this type of eye patch for use in eye examination procedures, however, because occluding devices for eye examinations do not require foam pads or adhering an occluder device in a way that completely obscure a patient's vision in the occluded eye.
Another example of a disposable occluding device is shown in U.S. Pat. No. 5,191,897 to Meshel, which is directed to a flat eye occluder that is temporarily adhered to a patient's face or spectacles. Meshel's occluder is configured to be adhered to a patient's face above the eye, and drape down over the eye. After use, the occluder is removed. Such an occluder may contact the patient's eye, eyelid, or eyelashes however, and cause some degree of interference with the eye or some degree of discomfort for the patient due to the contact. This is especially likely if the patient has long or bushy eyelashes. For example, prostaglandin analog (PGA) medications are used for the treatment of glaucoma and may cause eyelash growth. Patients who have received PGA treatments and who have long or bushy eyelashes may find that occluding devices such as Meshel's occluder cause interference or discomfort during use.